a) Field of the Invention
The invention concerns a detection device for determining whether a digital or analog audio signal processing apparatus is connected to the detection device; a microphone having such a detection device; an XLR plug with such a detection device and an audio signal processing arrangement with such a detection device.
b) Description of the Related Art
Microphones with both an analog output and also microphones with a digital output are known. The interface of a microphone with an analog output is described in the standard IEC 268 and the interface of a digital microphone is described in the standard AES 42.
As general state of the art, attention is to be directed to DE 42 07 447 A1, DE 196 00 404 A1, DE 44 27 396 A1 and DE 196 06 261 C2.
In the known microphones, a distinction is drawn between electrodynamic sound transducers and microphones with electrostatic sound transducers. The electrodynamic sound transducers generally pass the unamplified output signal directly to subsequent audio signal processing arrangements. Such microphones therefore do not require any internal or external feed voltage.
Microphones with electrostatic sound transducers such as, for example, capacitor or electret microphones in contrast require an internal or external voltage supply for operation of their internal amplifier. The signal coming from the electrostatic sound transducer is amplified and then fed to the following audio signal processing arrangements.
The following audio signal processing arrangements can include, for example, microphone (pre-) amplifiers, amplifiers, mixing desks, magnetic tape recording arrangements, hard disk recorders, so-called stage boxes which stand on a stage and other signal processing arrangements which have amplifiers, analog/digital converters (DAC), filters or the like. To reduce the cables required for the microphones, the habit has been adopted in many areas of ensuring the power supply for the microphones with a so-called phantom feed in accordance with IEC 268. In that case, the cable between the microphone and the subsequent signal processing means, which is usually employed for transmission of the audio signals from the microphone to the subsequent signal processing means, is also used to provide the signal voltage for the microphone through the subsequent signal processing means. In the case of analog microphones and analog signal processing arrangements that voltage is 48 volts.
A supply voltage of 10 volts is prescribed, however, for microphones with a digital output, in above-mentioned standard AES 42. That supply voltage for the digital signal output of a microphone, as described above, is afforded by the subsequent signal processing arrangement by way of the cable between the microphone and the signal processing arrangement. The standard for the digital interface between microphone and signal processing arrangement (AES 42) further provides for transmission of a dialog protocol (DPP) for determining status and setting the corresponding parameters such as for example sampler rate, impact-sound filter and the like.
Usually the XLR plugs and cables which are already used for analog microphones are also used for digital microphones. In practice, however, that gives rise to certain problems in regard to handling both analog and also digital microphones and audio signal processing arrangements. In particular, that can involve a confusion of digital and analog microphones, which leads to considerable uncertainty in terms of handling such microphones. That can give rise to problems, in particular, when the users do not have sufficient time to test the respective microphones or signal processing arrangements to ascertain whether they are designed for analog or digital operation.